Patna: Bihar is likely to receive below-normal rainfall during the 2026 southwest monsoon season, according to the latest long-range forecast released by the India Meteorological Department (IMD).
The forecast, issued by Patna Meteorological Centre, indicates that both the June-September monsoon season and the month of June are expected to witness rainfall below the long-period average across most parts of the state.
The IMD has also projected below-normal seasonal rainfall across India as a whole, estimating total monsoon precipitation at around 90% of the Long Period Average (LPA), with a model error margin of ±4%. The department said there is a higher probability of the country receiving less-than-normal rainfall during the southwest monsoon season.
Bihar Expected to Receive Less Rain Than Usual
According to the forecast, Bihar is among the regions where below-normal rainfall is considered the most likely outcome during the June-September monsoon period. The rainfall outlook map released by the IMD places much of the state in the category favouring below-normal precipitation.
The outlook for June is similarly cautious. The IMD said most parts of Bihar are likely to receive below-normal rainfall during the month, when the state’s average rainfall is around 163.3 mm.
El Niño Conditions May Influence Monsoon
Meteorologists attributed the forecast largely to evolving conditions in the equatorial Pacific Ocean.
The IMD said neutral El Niño-Southern Oscillation (ENSO) conditions are currently transitioning towards El Niño conditions. Climate models suggest that El Niño may develop during the southwest monsoon season, a phenomenon that is often associated with weaker monsoon rainfall over India.
Meanwhile, neutral conditions are prevailing over the Indian Ocean Dipole (IOD), and forecasts indicate that these neutral conditions are likely to continue through the monsoon season.
Temperature Outlook for June
The department expects maximum temperatures across Bihar to remain near normal during June. The state’s average daytime temperature during the month typically ranges between 35°C and 37°C.
However, minimum temperatures are likely to remain above normal across much of the state. Bihar’s average minimum temperature during June generally ranges from 26°C to 28°C.
Possibility of More Heatwave Days
The IMD has also warned that some isolated parts of Bihar could experience a higher-than-normal number of heatwave days during June. While the forecast does not suggest widespread heatwave conditions, certain pockets of the state may witness more frequent spells of extreme heat.
The department said it will issue its forecast for July rainfall during the final week of June.
The forecast comes at a time when farmers and policymakers are closely monitoring monsoon developments, given the crucial role seasonal rainfall plays in Bihar’s agriculture-dependent economy.
